Optical information recording apparatus, optical information recording medium, optical information recording method, and computer-readable information storage medium

ABSTRACT

An optical information recording apparatus for recording information on an optical information recording medium with multiple recording layers is disclosed. The optical information recording apparatus, performing an OPC operation before performing the recording, includes a reading part reading information on the type of the medium recorded thereon, a storage unit storing information on a recording condition at the time of performing the OPC operation for each recording layer with respect to each medium type, a recording condition obtaining part reading out the recording condition corresponding to the read type when the recording condition is stored in the storage unit, and reading the recording condition recorded in a corresponding one of the recording layers recording their respective recording conditions when the recording condition is not stored in the storage unit, and an OPC performance part performing the OPC operation using the obtained recording condition.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a U.S. continuation application filed under 35 USC111(a) claiming benefit under 35 USC 120 and 365(c) of PCT applicationJP2004/003403, filed Mar. 15, 2004, which claims priority to JapanesePatent Applications No. 2003-083368, filed on Mar. 25, 2003, and No.2004-002339, filed on Jan. 7, 2004. The foregoing applications arehereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to optical information recordingapparatuses, optical information recording media, optical informationrecording methods, and computer-readable information storage media, andmore particularly to an optical information recording apparatus, anoptical information recording medium, an optical information recordingmethod, and a computer-readable information storage medium for recordinginformation on an optical information recording medium having multiplerecording layers on each of which recording is performable.

2. Description of the Related Art

The structure of a recording medium whose recording layer has amultilayer structure and a recording and reproduction method thereforare disclosed in, for instance, Japanese Laid-Open Patent ApplicationNo. 11-195243.

A technique for recording, on each data layer of an optical medium ofmultilayer structure, information characteristic of the data layer isdisclosed in Japanese Laid-Open Patent Application No. 2002-50053.

Further, OPC (Optimum Power Control) for an optical disk of multilayerstructure is disclosed in Japanese Laid-Open Patent Application No.2000-311346.

SUMMARY OF THE INVENTION

With the spread of multimedia, playback-only media (recording media)such as music CDs, CD-ROMs, and lately, DVD-ROMs and informationreproduction apparatuses therefor have been put to practical use.Further, in recent years, phase change media as well as write-onceoptical disks using dye media and rewritable magneto-optical (MO) disksusing MO media have attracted attention, and information recording andreproduction apparatuses using these recording media have been put topractical use. Further, rewritable DVD media have attracted greatattention as next-generation multimedia recording media andlarge-capacity storage media.

Information is recorded on phase change media by changing the phase oftheir recording material reversibly between crystalline and amorphousphases. Unlike MO media, information can be recorded on and reproducedfrom phase change media with only laser light from a light sourcecomposed of a semiconductor laser without requiring an external magneticfield. Further, overwrite recording, by which information recording anderasure are simultaneously performed with laser light, is performable onphase change media.

General recording waveforms for recording information on dye mediainclude, for instance, a single-pulse semiconductor laser light emissionwaveform generated based on the eight-to-sixteen modulation code.However, single-pulse recording with this recording waveform causes aproblem in that teardrop-like distortion occurs in recording marksbecause of heat storage. Accordingly, as shown in FIG. 8C, a method thatforms marks on dye media with laser light of a multi-pulse waveformbased on recording data of, for instance, the EFM modulation code hasbeen proposed as an LD light emission waveform regulation (strategy) forrecording information on dye media. A method that forms the mark part ofthe multi-pulse waveform of a starting heating pulse and multiplesubsequent successive heating pulses has been proposed. FIG. 8A shows achannel clock signal, FIG. 8B shows an eight-to-sixteen modulatedsignal, and FIG. 8C shows a light waveform.

In general, the optimum value of recording power in the case ofperforming recording on optical recording media varies depending onambient temperature, the recording medium type, and linear velocity.Accordingly, in general, optical information recording apparatusesperform optimization of recording power by trial writing called OPC(Optimum Power Control) at the time of performing recording on dye mediaand phase change media. OPC is performed by recording predeterminedinformation in a predetermined region of a recording medium called PCA(Power Calibration Area) and reproducing the predetermined information.

Specifically, test data of a predetermined pattern formed of marks andspaces, 3 to 14 times the period T of the channel clock signal (3T to14T), is recorded by varying light emission power with several levels.The test data is reproduced, and the DC modulation of an RF signal andthe asymmetry of the RF signal after AC coupling at each power level arecalculated as evaluation standards. For instance, modulation M iscalculated as:M=Ip−p/Imax,  (1)where Ip−p is the maximum amplitude of the RF signal and Imax is themaximum value of the RF signal.

Further, asymmetry β after AC coupling is expressed, using the positivepeak level X1 and the negative peak level X2 of the RF signal after ACcoupling, as:β=(X1+X2)/(X1−X2),  (2)where “X1+X2” indicates the difference between the positive and negativepeak levels of the RF signal after AC coupling, and “X1−X2” indicatesthe peak-to-peak value of the RF signal after AC coupling.

Optimum recording power is obtained based on this modulation M orasymmetry β after AC coupling.

In the case of recording information on a write-once or rewritablemedium, it is necessary to set recording conditions corresponding to thetype of the medium. Here, the recording conditions are generally arecording power set value and a recording pulse shape applied at thetime of performing OPC. If the type (such as a manufacturer's name andtype identification information) of a medium to be subjected torecording can be identified in an optical information recordingapparatus, the recording conditions corresponding to the medium may beprestored in the memory of the optical information recording apparatus.In DVD+R and DVD+RW media, the manufacturer and the type of a medium arepre-recorded in a wobble signal recorded in a pregroove formed on therecording track called ADIP (Address In Groove) of a predeterminedregion.

If the optical information recording apparatus cannot identify a mediumtype (in the case of an unknown medium), a recording power set value anda recording pulse waveform at the time of OPC are determined based onthe ADIP information of the predetermined region, in which informationrecording conditions identified by the manufacturer of the medium arerecorded.

By the way, the technique of forming a recording surface in multiplelayers is known as an approach to recording more information on opticalrecording media than conventionally. DVD-ROM media with a recordingsurface of double-layer structure have been put to practical use already(see above-mentioned Japanese Laid-Open Patent Application No. 11-195243for the structure of a recordable medium with a recording layer ofmultilayer structure and a recording and reproduction method therefor).

In the case of multilayer write-once or rewritable media, each recordinglayer has a different recording characteristic. Therefore, it isnecessary to set recording conditions corresponding to each layer.

If the optical information recording apparatus can identify a mediumtype, recording conditions corresponding to each recording layer of themedium type may be prestored in the memory of the optical informationrecording apparatus. However, in the case of an unknown medium whosetype cannot be identified by the optical information recordingapparatus, recording conditions cannot be set differently for eachrecording layer in an optimum manner, thus causing a decrease inrecording quality.

In this respect, if in a medium, each recording layer has its recordingconditions recorded thereon as in the technology disclosed in the abovesecond patent-related document, it is possible to respond by reading therecording conditions recorded in the recording layer even if the mediumis unknown to the optical information recording apparatus.

However, an attempt to set recording conditions uniformly by readingrecording conditions recorded on each recording layer irrespective ofmedium type causes a problem in that a medium in which each recordinglayer does not have its recording conditions recorded thereon cannot besupported even when the medium is not unknown.

Further, in the case of, for instance, double-layer media, light istransmitted through the first-layer recording layer so that informationis recorded on the second layer. This causes a problem in that theamount of light reaching the second layer varies depending on whetherthe first layer is in an erased state (high reflectance) or a recordedstate (low reflectance), thus varying optimum recording power.

An object of the present invention is to make it possible to support anoptical information recording medium even if each recording layer doesnot have its recording conditions recorded thereon.

Another object of the present invention is to make it possible toperform optimum OPC in this case irrespective of whether the same regionin a recording layer other than a recording layer on which OPC is to beperformed is in an erased state or a recorded state.

The above objects of the present invention are achieved by an opticalinformation recording apparatus for recording information on an opticalinformation recording medium having a structure of multiple recordinglayers on each of which recording is performable, the opticalinformation recording apparatus performing a predetermined OPC operationin advance at a time of performing the recording, the opticalinformation recording apparatus including: a reading part configured toread information on a type of the optical information recording medium,the information being recorded on the optical information recordingmedium; a storage unit configured to store information on a recordingcondition at a time of performing the predetermined OPC operation foreach of the recording layers with respect to one or each of a pluralityof types of optical information recording media; a recording conditionobtaining part configured to read out the recording conditioncorresponding to the read type when the recording condition is stored inthe storage unit, and read the recording condition recorded in acorresponding one of the recording layers of the optical informationrecording medium, the recording layers recording the respectiverecording conditions thereof, when the recording condition is not storedin the storage unit; and an OPC performance part configured to performthe predetermined OPC operation using the obtained recording condition.

Preferably, the above-described optical information recording apparatusfurther includes a determination part configured to determine whether asame area in one of the recording layers other than the correspondingone of the recording layers on which the predetermined OPC operation isto be performed is in an erased state or a recorded state, wherein withrespect to each of the recording layers, the storage unit stores theinformation on the recording condition for each of a case where theother one of the recording layers is in the erased state and a casewhere the other one of the recording layers is in the recorded state,and the recording condition obtaining part, at a time of reading out therecording condition stored in the storage unit, reads out the recordingcondition of the case of the erased state or the case of the recordedstate in accordance with the determination, and at a time of reading therecording condition recorded in the corresponding one of the recordinglayers, reads one of the recording conditions recorded in thecorresponding one of the recording layers in accordance with thedetermination, the recording conditions being of the case where theother one of the recording layers is in the erased state and the casewhere the other one of the recording layers is in the recorded state,respectively.

In the above-described optical information recording apparatus, therecording condition preferably includes at least a recording power setvalue at the time of performing the predetermined OPC operation.

In the above-described optical information recording apparatus, therecording condition preferably includes at least a recording pulse shapeat the time of performing the predetermined OPC operation.

In the above-described optical information recording apparatus, therecording condition preferably includes at least a recording lightwavelength at the time of performing the predetermined OPC operation.

In the above-described optical information recording apparatus, therecording condition preferably includes at least a maximum recordingrate at the time of performing the predetermined OPC operation.

The above objects of the present invention are also achieved by anoptical information recording medium having a structure of multiplerecording layers on each of which recording is performable, wherein: ineach of the recording layers, a recording condition at a time ofperforming a predetermined OPC operation on the recording layer isrecorded for each of a case where one of the recording layers other thanthe recording layer is in an erased state and a case where the other oneof the recording layers is in a recorded state.

The above objects of the present invention are also achieved by anoptical information recording method for recording information on anoptical information recording medium having a structure of multiplerecording layers on each of which recording is performable, the opticalinformation recording method performing a predetermined OPC operation inadvance at a time of performing the recording, the optical informationrecording method including: a reading step of reading information on atype of the optical information recording medium, the information beingrecorded on the optical information recording medium; a recordingcondition obtaining step of, referring to a storage unit configured tostore information on a recording condition at a time of performing thepredetermined OPC operation for each of the recording layers withrespect to one or each of a plurality of types of optical informationrecording media, reading out the recording condition corresponding tothe type read in the reading step when the recording condition is storedin the storage unit, and reading the recording condition recorded in acorresponding one of the recording layers of the optical informationrecording medium, the recording layers recording the respectiverecording conditions thereof, when the recording condition is not storedin the storage unit; and an OPC performance step of performing thepredetermined OPC operation using the recording condition obtained bythe recording condition obtaining step.

Preferably, the above-described optical information recording methodfurther includes a determination step of determining whether a same areain one of the recording layers other than the corresponding one of therecording layers on which the predetermined OPC operation is to beperformed is in an erased state or a recorded state, wherein withrespect to each of the recording layers, the storage unit stores theinformation on the recording condition for each of a case where theother one of the recording layers is in the erased state and a casewhere the other one of the recording layers is in the recorded state,and the recording condition obtaining step, at a time of reading out therecording condition stored in the storage unit, reads out the recordingcondition of the case of the erased state or the case of the recordedstate in accordance with the determination, and at a time of reading therecording condition recorded in the corresponding one of the recordinglayers, reads one of the recording conditions recorded in thecorresponding one of the recording layers in accordance with thedetermination, the recording conditions being of the case where theother one of the recording layers is in the erased state and the casewhere the other one of the recording layers is in the recorded state,respectively.

In the above-described optical information recording method, therecording condition preferably includes at least a recording power setvalue at the time of performing the predetermined OPC operation.

In the above-described optical information recording method, therecording condition preferably includes at least a recording pulse shapeat the time of performing the predetermined OPC operation.

In the above-described optical information recording method, therecording condition preferably includes at least a recording lightwavelength at the time of performing the predetermined OPC operation.

In the above-described optical information recording method, therecording condition preferably includes at least a maximum recordingrate at the time of performing the predetermined OPC operation.

According to the above-described present invention, a recordingcondition corresponding to a recording layer of an optical informationrecording medium can be obtained from the recording layer. Accordingly,it is possible to perform OPC on each recording layer under an optimumrecording condition therefor. However, when the optical informationrecording medium is a known one stored in a storage unit, a recordingcondition of the optical information recording medium prestored in thestorage unit is employed. Therefore, even if the recording condition ofa recording layer is not recorded in the recording layer in the opticalinformation recording medium, it is possible to support the opticalinformation recording medium.

Further, the above-described present invention may be configured so thatoptimum OPC can be performed irrespective of whether the same area in arecording layer other than a recording layer on which OPC is to beperformed is in an erased state or a recorded state.

Further, the above-described present invention may be configured so thatOPC can be performed with a recording power set value at the time ofperforming OPC being optimized.

Further, the above-described present invention may be configured so thatOPC can be performed with a recording pulse shape at the time ofperforming OPC being optimized.

Further, the above-described present invention may be configured so thatOPC can be performed with a recording light wavelength at the time ofperforming OPC being optimized.

Further, the above-described present invention may be configured so thatOPC can be performed with a maximum recording rate at the time ofperforming OPC being optimized.

Further, according to the present invention, optimum OPC can beperformed irrespective of whether the same area in a recording layerother than a recording layer on which OPC is to be performed is in anerased state or a recorded state.

The above objects of the present invention are also achieved by acomputer-readable information storage medium storing a program forcausing a computer to execute an operation of controlling an opticalinformation recording apparatus for recording information on an opticalinformation recording medium having a structure of multiple recordinglayers on each of which recording is performable, the opticalinformation recording apparatus performing a predetermined OPC operationin advance at a time of performing the recording, the program includinginstructions to cause the computer to operate as: a reading partconfigured to read information on a type of the optical informationrecording medium, the information being recorded on the opticalinformation recording medium; a recording condition obtaining partconfigured to read out a recording condition corresponding to the readtype when the recording condition is stored in a storage unit storinginformation on a recording condition at a time of performing thepredetermined OPC operation for each of the recording layers withrespect to one or each of a plurality of types of optical informationrecording media, and read the recording condition recorded in acorresponding one of the recording layers of the optical informationrecording medium, the recording layers recording the respectiverecording conditions thereof, when the recording condition is not storedin the storage unit; and an OPC performance part configured to performthe predetermined OPC operation using the recording condition obtainedby the recording condition obtaining part.

Preferably, in the above-described computer-readable information storagemedium, the program further causes the computer to operate as adetermination part configured to determine whether a same area in one ofthe recording layers other than the corresponding one of the recordinglayers on which the predetermined OPC operation is to be performed is inan erased state or a recorded state, and when the program causes thecomputer to operate as the recording condition obtaining part, theprogram causes the computer to read out, at a time of reading out therecording condition stored in the storage unit storing, with respect toeach of the recording layers, the information on the recording conditionfor each of a case where the other one of the recording layers is in theerased state and a case where the other one of the recording layers isin the recorded state, the recording condition of the case of the erasedstate or the case of the recorded state in accordance with thedetermination, and at a time of reading the recording condition recordedin the corresponding one of the recording layers, read one of therecording conditions recorded in the corresponding one of the recordinglayers in accordance with the determination, the recording conditionsbeing of the case where the other one of the recording layers is in theerased state and the case where the other one of the recording layers isin the recorded state, respectively.

In the above-described computer-readable information storage medium, therecording condition preferably includes at least a recording power setvalue at the time of performing the predetermined OPC operation.

In the above-described computer-readable information storage medium, therecording condition preferably includes at least a recording pulse shapeat the time of performing the predetermined OPC operation.

In the above-described computer-readable information storage medium, therecording condition preferably includes at least a recording lightwavelength at the time of performing the predetermined OPC operation.

In the above-described computer-readable information storage medium, therecording condition preferably includes at least a maximum recordingrate at the time of performing the predetermined OPC operation.

By causing a computer to execute a program stored in a storage mediumaccording to the above-described present inventions, the same effects asdescribed above can be produced.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome more apparent from the following detailed description when readin conjunction with the accompanying drawings, in which:

FIG. 1 is an explanatory diagram showing a structure of a mediumaccording to an embodiment of the present invention;

FIG. 2 is a block diagram showing a structure of an optical informationrecording and reproduction apparatus according to the embodiment of thepresent invention;

FIG. 3 is a block diagram showing a structure of a system control unitof the optical information recording and reproduction apparatus;

FIG. 4 is a flowchart of an operation performed by the opticalinformation recording and reproduction apparatus;

FIGS. 5A and 5B are explanatory diagrams illustrating OPC performed bythe optical information recording and reproduction apparatus;

FIG. 6 is a flowchart of another operation performed by the opticalinformation recording and reproduction apparatus;

FIG. 7 is an explanatory diagram showing another structure of themedium;

FIGS. 8A, 8B, and 8C are timing charts of a channel clock signal, aneight-to-sixteen modulated signal, and a light waveform, respectively,in the optical information recording and reproduction apparatus; and

FIG. 9 is a block diagram of electrical connections of a host computerwith the optical information recording and reproduction apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description is given below, with reference to the accompanyingdrawings, of an embodiment of the present invention.

FIG. 1 is an explanatory diagram illustrating a medium (an opticalinformation recording medium) on which recording and reproduction isperformed by an optical information recording and reproduction apparatus1 (see FIG. 2 and the following) that is this embodiment. This medium101 is a dye-based medium in which DVD-ROM format code data is ofdouble-layer structure of recording layers 102 and 103 as shown inFIG. 1. Mark-edge (PWM: Pulse Width Modulation) recording is performedusing the eight-to-sixteen modulation code as a data modulation method.In FIG. 1, a indicates an area where the medium information/recordingconditions of the first layer are recorded, and b indicates an areawhere the medium information/recording conditions of the second layerare recorded.

It is assumed that in the medium 101, track address information and thelike is recorded in a wobble signal recorded in a pregroove formed on arecording track in each of the recording layers 102 and 103.

FIGS. 2 and 3 are block diagrams illustrating the overall configurationof the information recording and reproduction apparatus 1, which is thisembodiment, and the configuration of a system control unit 10 thereof,respectively.

The optical information recording and reproduction apparatus 1, whichimplements an optical information recording apparatus of the presentinvention, performs information recording by forming recording marks bycausing a semiconductor laser to perform multi-pulse light emission,using the medium 101 as described with reference to FIG. 1 and recordingdata.

According to the optical information recording and reproductionapparatus 1, at the time of information reproduction, an LD (laserdiode) light source 2 is driven by an LD driving unit 6 so that the LDlight source 2 emits light at reproduction power (read power). In anoptical pick up not graphically represented, the light of reproductionpower from the LD light source 2 is emitted so as to be focused on thepredetermined layer 102 or 103 (see FIG. 1) of the medium 101 viapredetermined optical elements 3, 4, and 5. Its reflected light isreceived by a light-receiving element 8 via the predetermined opticalelements 5 and 4 and a predetermined optical element 7 so as to besubjected to photoelectric conversion. A current signal after theconversion is subjected to IV conversion and amplified in an IVamplifier 9, and a reproduction signal (an RF signal) 41 is obtained.

Further, part of the emitted light of the LD light source 2 enters amonitor PD (photodiode) 12 via a predetermined optical element 11 andthe like, and a monitor current proportional to light emission power issubjected to IV conversion by an IV amplifier 13. By using an amplifiedpower monitor signal 42, APC control can be performed.

At the time of information recording, a host controller 21 generates apulse control signal 43 based on recording data formed of theeight-to-sixteen modulation code. The LD driving unit 6 drives the LDlight source 2 with a driving current according to the pulse controlsignal 43 so that multi-pulse light as shown in FIG. 8C is emitted andthe predetermined recording layer 102 or 103 of the medium 101 isilluminated therewith. As a result, recording marks are formed on themedium 101 so that information is recorded thereon. The host controller21 outputs a bias level current driving signal 44 and a peak levelcurrent overlapping signal 45 to the LD driving unit 6 in order tocontrol the light emission level of space/peak power.

The host controller 21 is a control unit that is formed mainly of amicrocomputer and controls the entire optical information recording andreproduction apparatus 1. A peak/bottom detection circuit 22 detects thepeaks and the bottoms of the RF signal 41, and outputs them to the hostcontroller 21. A data decoder 23 decodes the RF signal 41 and outputs itto the host controller 21. A data encoder 24 encodes recordinginformation from the host controller 21. An LD waveform control circuit25 drives the LD driving unit 6 so as to control the waveform of laserlight output by the LD light source 2 based on the decoded information.Although a detailed description is omitted, the optical informationrecording and reproduction apparatus 1 includes an actuator, a drivingmechanism, and a control system of well-known configurations thatcontrol the optical pickup, which is not graphically represented, toperform a focus operation, a tracking operation, and a seek operation.

Next, a description is given, with reference to the flowchart of FIG. 4,of an operations procedure up to the recording of information in theoptical information recording and reproduction apparatus 1.

First, (the CPU of) the host controller 21 moves the optical pickup,which is not graphically represented, to the layer 102 or 103 to besubjected to recording of the medium 101 so as to obtain informationidentifying the type of the medium 101 (medium information recorded inthe areas of A and B of FIG. 1) from the target layer 102 or 103 (stepS1). As shown in FIG. 1, the management information area of the medium101 called Lead In area exists inside the recording area of each of thelayers 102 and 103 in the medium 101, and in one area therein, themedium information of the medium 101 is recorded as a wobble signal.This wobble signal makes it possible to obtain the name of themanufacturer of the medium 101 and medium information for identifyingthe medium type which information is provided by the manufacturer. Then,as the next processing, the area in the Lead In area is subjected toreproduction so that the medium information of the medium 101 isobtained from the wobble signal (a reading part, a reading step) (stepS2).

If the type of the medium 101 identified from the wobble signal is amedium known to the optical information recording and reproductionapparatus 1 (is prestored in the ROM or the like of the host controller21) (YES of step S3), values stored as table data in the storage of thehost controller 21, such as the ROM, individually for the type of themedium 101 are determined as recording conditions (a recording power setvalue, a recording pulse shape, the light wavelength of recording light[a laser wavelength], a maximum recording rate, and the like at the timeof performing OPC) (a recording condition obtaining part, a recordingcondition obtaining step) (step S4). The recording conditions are storedin the ROM or the like for each of the recording layers 102 and 103 ofthe medium 101 for each type of the medium 101.

If the medium 101 is an unknown medium that is not prestored in the ROMor the like of the optical information recording apparatus 1 (NO of stepS3), recording conditions recorded by the wobble signal in the Lead Inarea of the medium 101 (recorded in the areas of a and b of FIG. 1) areread out (the recording condition obtaining part, the recordingcondition obtaining step) (step S5). The recording conditions arerecorded for each of the recording layers 102 and 103 of the medium 101(the recording conditions of the recording layer 102 are recorded in thearea of a of the same recording layer 102, and the recording conditionsof the recording layer 103 are recorded in the area of b of the samerecording layer 103).

Then, based on the recording conditions obtained in step S4 or S5, OPCconditions and a recording pulse waveform are set (step S6). Here, theOPC conditions are a central power value in the case of recording withvarying power and target asymmetry (β). In the case of known media, asthese values, suitable values may be pre-obtained empirically for eachtype of the media and prestored in the ROM or the like in the opticalinformation recording and reproduction apparatus 1. If the medium 101 isan unknown medium not stored in the ROM in the optical informationrecording and reproduction apparatus 1, values obtained from the wobblesignal obtained in step S2 may be directly used. However, it isdesirable to determine by multiplying the values by a predeterminedcoefficient.

Next, in order to determine optimum recording power, prior to aninformation recording operation, OPC is performed in the recording areaand the OPC area of the layer 102 or 103 to be subjected to recording(see FIG. 1) (step S7).

At the time of performing OPC, at every sector switching, the hostcontroller 21 generates a sector synchronization signal 46 as shown inFIG. 5A, and at every generation of the sector synchronization signal46, updates the peak level current overlapping signal 44 so as to varythe light emission power of the LD light source 2 step by step as shownin FIG. 5B. After the completion of the recording with the lightemission power being varied step by step, the areas subjected to therecording are subjected to reproduction, and the RF signal 41 is sampledin each sector. The host controller 21 performs calculations based onthe above-described Eq. (2) or the like so that asymmetry (β) iscalculated in each sector, and determines light emission power at thetime of a recording operation based on the calculated βs. FIG. 5A showsthe sector synchronization signal 46, and FIG. 5B shows a recordingwaveform at the time of OPC.

When the optimum recording power is thus determined by performing OPC,the information recording operation is performed by well-known means(step S8).

Thus, in the case of performing recording on the unknown medium 101 (NOof step S3), the recording conditions corresponding to each of therecording layers 102 and 103 may be obtained individually from the ADIPinformation of the medium 101. Accordingly, recording can be performedwith optimum recording setting conditions for each of the recordinglayers 102 and 103. However, in the case of the known medium 101recorded in the ROM or the like of the optical information recording andreproduction apparatus 1 (YES of step S3), the recording conditions ofthe medium 101 prestored in the ROM or the like are employed. Therefore,even if the recording conditions of the recording layers 102 and 103 arenot recorded in the recording layers 102 and 103, respectively, in theknown medium 101, the known medium 101 can be supported.

Instead of the operation of FIG. 4, an operation shown in the nextflowchart of FIG. 6 may be performed. That is, in the target medium 101in this case, with respect to the recording conditions recorded in theLead In area of each of the recording layers 102 and 103, two types arerecorded according to whether the recording state of the other layer 103or 102 is an erased state or a recorded state as shown in FIG. 7(regions of a′, a″, b′ and b″ of FIG. 7). Likewise, with respect to therecording conditions stored in the ROM or the like of the hostcontroller 21, two types of recording conditions are stored for each ofthe recording layers 102 and 103. In FIG. 7, a indicates an area wherethe medium information of the first layer is recorded, b indicates anarea where the medium information of the second layer is recorded, a′indicates an area where the multilayer recording conditions of the firstlayer when the second layer is in an erased state are recorded, b′indicates an area where the multilayer recording conditions of thesecond layer when the first layer is in an erased state are recorded, b″indicates an area where the multilayer recording conditions of the firstlayer when the second layer is in a recorded state are recorded, and B″indicates an area where the multilayer recording conditions of thesecond layer when the first layer is in a recorded state are recorded.

In the case of recording information, in FIG. 6, steps with the samenumerals as in FIG. 4 are the same operations as in the case of FIG. 4,and a detailed description thereof is omitted. In the operation of FIG.6, first, before performing OPC (step S7), it is determined whether thesame area in the other recording layer 102 or 103 as the area to besubjected to OPC is in an erased state or a recorded state (adetermination part, a determination step) (step S9). According thereto,one of the above-described two types of recording conditions isemployed, and the settings of OPC conditions and a recording pulsewaveform are switched (step S6). For instance, when recording isperformed on each of the recording layers 102 and 103 and informationindicating that recording has been performed is recorded in the Lead Inarea or the like, the determination of step S9 can be performed byreading the information recorded in the Lead In area or the like.Alternatively, it may also be performed by determining the signal levelof the RF signal 41 in the host controller 21.

At the time of recording information (step S8), it is determined whetherthe same area in the other recording layer 102 or 103 as the area to besubjected to recording is in an erased state or a recorded state (thedetermination of step S9 may be employed as it is for this) (step S10),and according thereto, recording power and a light emission pulsewaveform are switched (step S11). The case where the light emissionpulse waveform may be constant irrespective of the recording state ofthe other recording layer 102 or 103 may be considered. In this case, anoperation switching only the recording power may be considered.

In the above description, the description is given taking the medium 101whose recording layer has a double-layer structure as an example.However, the same operation as described above may also be performedwhen the recording layer has a multilayer structure of three or morelayers. Further, in the above description, the description is giventaking the medium 101 that is a write-once dye medium as an example.However, the present invention is also applicable to phase change mediaand the like whose recorded information is rewritable because theoperation sequence can be considered entirely the same except for achange in the item of recording conditions.

Further, in the above-described embodiment, the description is givenwith a case in mind where a predetermined control program executed inthe microcomputer of the host controller 21 and implementing the programof the present invention is stored in the storage medium of the hostcontroller 21, such as a ROM, and characteristic processing performed bythe optical information recording apparatus and the optical informationrecording method of the present invention is implemented by processingperformed by the microcomputer based on the control program.

However, the present invention is not limited to this. That is, acontrol program implementing the program of the present invention may beprovided in a host computer, such as a personal computer, controllingthe optical information recording and reproduction apparatus 1, and theoptical information recording method of the present invention may beimplemented by the host computer controlling the optical informationrecording and reproduction apparatus 1 based on the control program.

An overview of such a system is given below with reference to FIG. 9.

As shown in FIG. 9, in a host computer 201, a CPU 211 performing avariety of calculations and centralized control of each part of the hostcomputer 201 and a memory 212 formed of various ROMs and RAMs areconnected by a bus 213.

To the bus 213, a magnetic storage device 214 such as a hard disk, aninput device 215 formed of a mouse, a keyboard and the like, a displayunit 216, a storage medium reading device 218 reading a storage medium217 such as an optical disk, and the optical information recording andreproduction apparatus 1 are connected via predetermined interfaces, anda predetermined communication interface (communication controller) 219performing communications with a network 202 is connected. As thestorage medium 217, a variety of media such as optical disks such as CDsand DVDs, magneto-optical disks, and flexible disks may be employed.Further, as the storage medium reading device 218, specifically, anoptical disk unit, a magneto-optical disk unit, a flexible disk unit, orthe like is employed depending on the type of the storage medium 217. Inthe case of employing an optical disk unit as the storage medium readingdevice 218, it may be implemented by the same apparatus as the opticalinformation recording and reproduction apparatus 1.

The host computer 201 reads programs 220 implementing the program of thepresent invention from the storage medium 217 implementing the storagemedium of the present invention, and installs them in the magneticstorage device 214. These programs 220 may be downloaded via the network202 or the Internet to be installed. By this installation, the hostcomputer 201 controls the optical information recording and reproductionapparatus 1 based on the programs 220 and realizes the above-describedcontrol contents characteristic of the present invention. That is theprograms 220 are the driver software and the like of the opticalinformation recording and reproduction apparatus 1. The programs 220 maybe those that operate on a predetermined OS.

The present invention is not limited to the specifically disclosedembodiment, and variations and modifications may be made withoutdeparting from the scope of the present invention.

1-19. (canceled)
 20. An optical information recording apparatus forrecording information on an optical information recording medium havinga structure of multiple recording layers on each of which recording isperformable, the optical information recording apparatus performing apredetermined OPC operation in advance at a time of performing therecording, the optical information recording apparatus comprising: areading part configured to read information on a type of the opticalinformation recording medium, the information being recorded on theoptical information recording medium; a storage unit configured to storeinformation on a recording condition for performing the predeterminedOPC operation for each of the recording layers with respect to one oreach of a plurality of types of optical information recording media; arecording condition obtaining part configured to read out the recordingcondition corresponding to the read type from the storage unit when thecorresponding recording condition is stored therein, and to read therecording condition recorded in a corresponding one of the recordinglayers of the optical information recording medium, the recording layersrecording the respective recording conditions thereof, and multiply theread recording condition by a predetermined coefficient when thecorresponding recording condition is not stored in the storage unit; andan OPC performance part configured to perform the predetermined OPCoperation using one of the recording condition read out from the storageunit and the multiplied recording condition.